His name is Jim Turner. His instruments are glasses - 55 of them, filled with water from a plastic milk bottle, tuned with a turkey-baster, and played up to six at a time by rubbing the rims with fingers dipped in distilled water.

''It's an incredible instrument that has almost disappeared,'' says the lanky , Montana-born musician. Recounting its 300-year history - including scores by composers ranging from Franz Joseph Haydn to John Philip Sousa - he notes that ''it was the rage of the 18th century.'' Marie Antoinette played musical glasses , he says, and Mozart gave his first concert on them at age 17. And Ben Franklin's glass harmonica, inspired by the simpler musical glasses, was an elaborate series of rotating glass hemispheres turned with a treadle.

One of only a handful of musical-glass players in the world, Mr. Turner began on the piano, but found that ''it wasn't the right sound.'' Then in high school, he says, ''I started to play the musical saw - the sound is so very pure if you play it right.'' Five years ago he moved to musical glasses, also attracted by their purity.

Some of the music comes from his own head - his jazzy version of ''The Saints ,'' for example. But much of it, like a Mozart quintet written for flute, oboe, viola, cello, and glass, is in the literature.

His reception at last season's student concerts in Philadelphia, where he and his wife live, was enthusiastic. ''Everyone adores him, including the orchestra and the conductor,'' says Ann Bloom of the Philadelphia Orchestra Association. ''They can't believe he's getting the sounds he gets.''

And the glasses themselves? Ordinary stemware. Crystal, says Mr. Turner, can ring for up to 30 seconds - blurring the sound, especially in fast passages.